In recent years, the number of people suffering from lifestyle-derived diseases such as hypertension is increasing rapidly due to western style diet and lifestyle pattern changes. The incidence of hypertension is gradually increasing worldwide.
It is known that the main causes of hypertension are increased peripheral vascular resistance, the action of endothelin (ET), the increase of free oxygen radicals and the action of nitric oxide, the contraction of blood vessels due to insulin resistance, and the renin-angiotensin system disturbance, etc. Among them, the renin-angiotensin system has been actively investigated recently. If the blood pressure gets low, renin converts angiotensinogen to angiotensin I, and angiotensin converting enzyme (ACE) converts angiotensin I into angiotensin II, an active hormone, thereby increasing blood pressure, activating sympathetic nerves and maintaining electrolyte balance. More specifically, the angiotensin converting enzyme (ACE) is an enzyme playing a role in converting angiotensin I, a decapeptide, to angiotensin II, a vasoconstrictor, by cutting dipeptide (His-Leu) from angiotensin I. a decapeptide. The increase of angiotensin II promotes strong blood pressure elevation action and secretion of aldosterone, an antidiuretic hormone, which inhibits the excretion of water and sodium and thus increases circulating blood volume, thereby inducing hypertension. In addition, ACE decomposes and inactivates bradykinin, a vascular relaxant, resulting in the elevation of blood pressure. Therefore, the ACE inhibitor has provided a breakthrough in the treatment of hypertension, which prevents vasoconstriction by inhibiting the action of ACE, thereby showing blood pressure-lowering effect. As a representative ACE inhibitor, captopril, a chemically synthesized agent, has been developed and used as a therapeutic agent for hypertension. However, it shows many adverse events such as dry cough, headache, loss of appetite, taste dysfunction, rash, decrease of leukocytes, etc., and thus, recent researches have been focused on the development of ACE inhibitors from a natural product which does not show adverse event. Although ACE inhibiting peptides derived from the plasma of slaughtered blood, as natural products, have been reported in Korea (Korean Patent No. 0215090 and Korean Patent No. 0215091), the research on ACE inhibiting substance from Ceriporia lacerata has not been known.
Ceriporia lacerata is a kind of white-rotting fungus and known to conduct co-metabolism, i.e., lignin decomposition, in order to use carbon sources such as cellulose, hemi-cellulose, other polysaccharides, and glycerol, etc., in the ecosystem. However, since Ceriporia lacerata was first reported to academic world in 2002, the research on the industrialization of Ceriporia lacerata has not been done sufficiently.
Accordingly, the present inventors have found that an extracellular polysaccharide produced by Ceriporia lacerata, a mycelial culture medium of Ceriporia lacerata containing the same, or dried powders or an extract thereof shows a blood pressure-lowering effect, and have completed the present invention which is related to a composition for lowering blood pressure, comprising the extracellular polysaccharide, the mycelial culture medium, the dried powders, or the extract, as an effective ingredient.